The North American Beaver (Castor canadensis)Is a rodent originating from North America. It is the only species of Beaver in America and one of two in the world. The other is located in Europe. The North American Beaver even though originating from North America has been introduced into the United States and South America to help conservation, although its conservation status is under least concerned. The North American Beaver is the largest rodent in North America, and 3rd largest in the world following the south American Capybara and the European Beaver . The North American Beaver is a large animal and a heavy one with a full grown adult weighing between 15 to 35 KG, whilst older Beavers can weigh up to 45 KG. The total body length of the beaver is usually around 1M including the length of its tail.
HABITAT
The North American Beaver is a semi-aquatic rodent meaning that much of its habitat is spent on land and under water. When the Beaver is on land it spends much of its time eating trees, and lots of them. The main part of the beavers diet consist of trees. Because of this lots of forests can be destroyed by the beaver as they need to eat lots of trees to survive the harsh north american winters. They also require many trees to construct their dams. The North American Beavers digestive track is very special enabling it to digest trees. They also eat lots of vegetation, meaning that the beaver is a herbivore.
As a beaver is a semi-aquatic organism, much of its life is spend under or in the water. North American Beavers naturally build dams in streams and rivers. These dams are built both as a defensive home for the beaver and to stimulate natural growth around the area. A beavers dam will slow down a river to a natural flowing stream, and will also raise the water level which will give surrounding areas with nutrients and moisture to turn it into a meadow. This is one positive impact of a Beavers dam, but there are some negatives including possible flooding and deforestation. Beavers require large amounts of materials to create these dams including trees and a lot of them. They can also build their dams using shrubs, and waste from humans including drink bottles and even plastic bags. A dam is usually a few feet tall, but some have been known to reach ten feet. They consist of two entrances, a center pod, and a small hole in the top to allow for ventilation. This can be seen in the image below.
Inside A Beaver Dam (source: http://animals.howstuffworks.com/mammals/beaver-dam.htm)
The North American Beavers are located in North America, mostly in Canada, but can also be found in areas ranging from Alaska to Florida to even Mexico. Although some of these areas have different climates, the North American Beaver can be suited in a range of climates ranging from below zero Celsius to above. They can survive this cold so well because of their thick pelt that covers their body. The North American Beaver had been introduced to Argentina, parts of Asia, and Europe and had both positive and negatives effects on the environment including natural deforestation and flooding. Although their new habitat in Europe was shared with the Eurasian Beaver they are unable to interbreed due to different counts in chromosomes. As Beavers became extremely endangered in the early 20th century, they have since regrown in population due to a decline in products made of the Beaver including clothing items and perfumes making them of least concern under the conversational status listing.
North American Beavers had been driven out of streams and river systems as human settlements sprang up centuries ago. Due to hunting, pollution and construction possible damming areas for the North American Beaver had become slim. This had forced them north wards and out of populated areas which had little impact on humans or beavers as they still had the same materials for living and were able to survive. This has changed as towns, cities and states look more towards the rehabilitation and conservation of these river systems to help the environment recuperate in popular areas. This means that the North American Beaver can slowly migrate back to where it once called home. This has happened in some areas including a Beaver in the Bronx River, New York City, also In Chicago Park District, and outside San Francisco in downtown Martinez. Beavers and their families have slowly migrated back with wide support and appreciation from the citizens, happy to see the return of the over sized rodent.
Beaver Dam in New York (source: http://en.wikipedia.org/wiki/File:Lincoln_Park_North_Pond_Beaver_Lodge_Dec_4,_2009.jpg)
ADAPTATIONS Behavioral 1
A Behavioral aspect of the Beaver is that it lives very closely with its family. After a beaver produces its 2 - 3 kits, usually in winter and after approximately 106 days of gestation, within its lodge, the kits stay with their parents for around two years where they learn how to construct dams and lodges, and learn to eat and survive. These two years are vital to the survival of the North American Beaver, because if they do not acquire this required knowledge from their parents they will not be able to survive and create homes and dams. One thing A North American Beaver does not need to learn from its parents is how to swim. This is because newborn kits fur is incredibly dense which makes them buoyant and therefore float incredibly easy. Evolution would have implemented this behavior of parenthood far back when the species evolved from an aquatic fish to a semi-aquatic organism, meaning that it would later be able to construct basic lodges from the surrounding materials. It is not proven that there were any contradicting factors when this behavioral pattern was established within the species.
Behavioral 2
Another Behavioral adaptation of the North American Beaver is its ability to build an incredibly 'ahead of its species' dam and lodge used to control the flow of water in and around its home, and to provide a defensive home that can stop attacks from prey including the Fox and wolf, however larger animals can destroy these lodgings with force including the Grizzly Bear.These Dams have actually been known to provide inspiration for structures for engineers as they are so solidly built and so durable and creative. As well as providing the Beaver with a home and safe haven from predators, these dams act as a very functional and natural controlling pod for rivers and streams that can slow down water flow creating a soil enriched meadow in the surrounding areas bringing new grown in the form of trees and shrubs. This Behavioral adaptation would have developed naturally as the animal required a place to reproduce, grow and live, so no real artificial or natural factors would have caused this behavioral adaptation. Although in some areas Beavers would have had to develop this skill as new breeds of predators could have been introduced into the surrounding areas, so a behavioral adaptation was gained that tells the Beaver to build its defensive lodge. Both aspects would have risen to this natural behavior.
A structural adaptation of the North American Beaver is its structure and body shape allowing it to be a very efficient swimmer both on and under water. A North American Beaver has hind webbed feet which are great for swimming, similar to diving swim shows that humans wear. There tail also acts as a large paddle that is used to push them along underwater. Their paddle tail is also used to slap the ground and water to warn their family of predators near by. The Beaver pelt is very thick and oily which gives the Beaver buoyancy and keeps it warm while being submerged for sometimes more than ten minutes. A nictitating membrane covers the Beavers eyes allowing it to see under water, whilst it is possible for the North American Beaver to seal its nostrils and ears whilst being submerged. These adaptations help the Beaver to swim underwater for long amounts of time, allowing it to construct underwater components of their dams and even possibly elude some of their predators. Natural environmental pressure that would have led to this adaptation would be the Behavioral aspect of a Beaver in which it must construct dams to survive and hide from predators. A Beaver cannot live without this ability to be a semi-aquatic rodent as it would not be able to construct its home and hide from predators.
A second structural adaptation the beaver would have gained through evolution is the shape and strength of their two front teeth. Their front teeth are very large for their body size, and this is one distinct recognizable aspect of the Beaver. Their front teeth have a bright orange surface because of the enamel that coats and protects them. Eventually their teeth are ground down to a chiseled edge due to the constant gnawing on trees. This may make the Beaver seem frightening but the North American Beaver is a herbivore and does not eat meat. These large and very strong teeth make it possible for the North American Beaver to chew through large trees at a relatively fast pace allowing them to construct their homes and lodges within days, and also allows them to get to the under lying parts of the tree that is the main source of the North American Beavers diet. Environmental pressures that would have caused this would not exist. The need to eat and chop down trees as a home and food source would have caused this adaptation. The Beaver needed to build its home, and needed to eat, so they developed large strong teeth so they could chop down trees quick and efficiently.
Physiological
A physiological adaptation that the North American Beaver has is its warm blood. Being warm blooded allows the North American Beaver to stay underwater for long times without getting cold and getting hypothermia. As long as the Beaver keeps its energy levels up its internal systems can keep generating heat so that the Beaver can keep warm under water. This also benefits if the surroundings are warm. The Beaver can cool itself to remain at a comfortable temperature and continue on with building its lodge and keeping its family safe. The environmental pressure that would give the North American Beaver warm blood would come from its ancestor, the Ancient Giant Beaver. This Beaver was tested by nature and put through an ice age, and its warm blood kept it alive. This trait was passed through to the North American Beaver.
Other Information
These days the North American Beaver is a symbol of Canada and renowned to be natures own engineer. Able to survive harsh weather, live comfortably within its own built lodge, and its ability to be a sufficient swimmer and land dweller makes the North American Beaver a very unique creature. The Beaver is recognized in many schools and communities for its skill and unique building. It is said that many engineers and designers use the Beaver as inspiration for structures as it is such a well build lodge built by nothing more than a large rodent.
Beaver on 5c Canadian Coin. (source: http://media.photobucket.com/image/canada%205%20cent/Theike2008/325%20COINS%20of%20the%20WORLD/Canada19685Cent.jpg?o=2)
Beaver - Castor canadensis - NatureWorks. (n.d.). New Hampshire Public Television - Engage. Connect. Celebrate.. Retrieved July 21, 2010, from http://www.nhptv.org/natureworks/beaver.htm
Beavers Natural Engineers. (n.d.). hsus. Retrieved July 21, 2010, from www.hsus.org/wildlife/a_closer_look_at_wildlife/beavers_natures_engineers.html
The Beaver. (n.d.). Straight talk about issues affecting America today: America's Christian Heritage, Separation of Church and State, Abortion, Evolution. Retrieved July 28, 2010, from http://www.straight-talk.net/evolution/beaver.htm
NORTH AMERICAN BEAVER
< Ancient Giant Beaver.. ............................................. ...Modern Urban Beaver >
(image(s) source: http://www.flickr.com/search/?w=all&q=north+american+beaver&m=text)
The North American Beaver (Castor canadensis) Is a rodent originating from North America. It is the only species of Beaver in America and one of two in the world. The other is located in Europe. The North American Beaver even though originating from North America has been introduced into the United States and South America to help conservation, although its conservation status is under least concerned. The North American Beaver is the largest rodent in North America, and 3rd largest in the world following the south American Capybara and the European Beaver . The North American Beaver is a large animal and a heavy one with a full grown adult weighing between 15 to 35 KG, whilst older Beavers can weigh up to 45 KG. The total body length of the beaver is usually around 1M including the length of its tail.
HABITAT
The North American Beaver is a semi-aquatic rodent meaning that much of its habitat is spent on land and under water. When the Beaver is on land it spends much of its time eating trees, and lots of them. The main part of the beavers diet consist of trees. Because of this lots of forests can be destroyed by the beaver as they need to eat lots of trees to survive the harsh north american winters. They also require many trees to construct their dams. The North American Beavers digestive track is very special enabling it to digest trees. They also eat lots of vegetation, meaning that the beaver is a herbivore.
As a beaver is a semi-aquatic organism, much of its life is spend under or in the water. North American Beavers naturally build dams in streams and rivers. These dams are built both as a defensive home for the beaver and to stimulate natural growth around the area. A beavers dam will slow down a river to a natural flowing stream, and will also raise the water level which will give surrounding areas with nutrients and moisture to turn it into a meadow. This is one positive impact of a Beavers dam, but there are some negatives including possible flooding and deforestation. Beavers require large amounts of materials to create these dams including trees and a lot of them. They can also build their dams using shrubs, and waste from humans including drink bottles and even plastic bags. A dam is usually a few feet tall, but some have been known to reach ten feet. They consist of two entrances, a center pod, and a small hole in the top to allow for ventilation. This can be seen in the image below.
The North American Beavers are located in North America, mostly in Canada, but can also be found in areas ranging from Alaska to Florida to even Mexico. Although some of these areas have different climates, the North American Beaver can be suited in a range of climates ranging from below zero Celsius to above. They can survive this cold so well because of their thick pelt that covers their body. The North American Beaver had been introduced to Argentina, parts of Asia, and Europe and had both positive and negatives effects on the environment including natural deforestation and flooding. Although their new habitat in Europe was shared with the Eurasian Beaver they are unable to interbreed due to different counts in chromosomes. As Beavers became extremely endangered in the early 20th century, they have since regrown in population due to a decline in products made of the Beaver including clothing items and perfumes making them of least concern under the conversational status listing.
North American Beavers had been driven out of streams and river systems as human settlements sprang up centuries ago. Due to hunting, pollution and construction possible damming areas for the North American Beaver had become slim. This had forced them north wards and out of populated areas which had little impact on humans or beavers as they still had the same materials for living and were able to survive. This has changed as towns, cities and states look more towards the rehabilitation and conservation of these river systems to help the environment recuperate in popular areas. This means that the North American Beaver can slowly migrate back to where it once called home. This has happened in some areas including a Beaver in the Bronx River, New York City, also In Chicago Park District, and outside San Francisco in downtown Martinez. Beavers and their families have slowly migrated back with wide support and appreciation from the citizens, happy to see the return of the over sized rodent.
ADAPTATIONS
Behavioral 1
A Behavioral aspect of the Beaver is that it lives very closely with its family. After a beaver produces its 2 - 3 kits, usually in winter and after approximately 106 days of gestation, within its lodge, the kits stay with their parents for around two years where they learn how to construct dams and lodges, and learn to eat and survive. These two years are vital to the survival of the North American Beaver, because if they do not acquire this required knowledge from their parents they will not be able to survive and create homes and dams. One thing A North American Beaver does not need to learn from its parents is how to swim. This is because newborn kits fur is incredibly dense which makes them buoyant and therefore float incredibly easy. Evolution would have implemented this behavior of parenthood far back when the species evolved from an aquatic fish to a semi-aquatic organism, meaning that it would later be able to construct basic lodges from the surrounding materials. It is not proven that there were any contradicting factors when this behavioral pattern was established within the species.
Behavioral 2
Another Behavioral adaptation of the North American Beaver is its ability to build an incredibly 'ahead of its species' dam and lodge used to control the flow of water in and around its home, and to provide a defensive home that can stop attacks from prey including the Fox and wolf, however larger animals can destroy these lodgings with force including the Grizzly Bear.These Dams have actually been known to provide inspiration for structures for engineers as they are so solidly built and so durable and creative. As well as providing the Beaver with a home and safe haven from predators, these dams act as a very functional and natural controlling pod for rivers and streams that can slow down water flow creating a soil enriched meadow in the surrounding areas bringing new grown in the form of trees and shrubs. This Behavioral adaptation would have developed naturally as the animal required a place to reproduce, grow and live, so no real artificial or natural factors would have caused this behavioral adaptation. Although in some areas Beavers would have had to develop this skill as new breeds of predators could have been introduced into the surrounding areas, so a behavioral adaptation was gained that tells the Beaver to build its defensive lodge. Both aspects would have risen to this natural behavior.
North American Beaver building its dam. (source: http://www.youtube.com/watch?v=fgUIpezLWV0)
Structural 1
A structural adaptation of the North American Beaver is its structure and body shape allowing it to be a very efficient swimmer both on and under water. A North American Beaver has hind webbed feet which are great for swimming, similar to diving swim shows that humans wear. There tail also acts as a large paddle that is used to push them along underwater. Their paddle tail is also used to slap the ground and water to warn their family of predators near by. The Beaver pelt is very thick and oily which gives the Beaver buoyancy and keeps it warm while being submerged for sometimes more than ten minutes. A nictitating membrane covers the Beavers eyes allowing it to see under water, whilst it is possible for the North American Beaver to seal its nostrils and ears whilst being submerged. These adaptations help the Beaver to swim underwater for long amounts of time, allowing it to construct underwater components of their dams and even possibly elude some of their predators. Natural environmental pressure that would have led to this adaptation would be the Behavioral aspect of a Beaver in which it must construct dams to survive and hide from predators. A Beaver cannot live without this ability to be a semi-aquatic rodent as it would not be able to construct its home and hide from predators.
Structural 2
A second structural adaptation the beaver would have gained through evolution is the shape and strength of their two front teeth. Their front teeth are very large for their body size, and this is one distinct recognizable aspect of the Beaver. Their front teeth have a bright orange surface because of the enamel that coats and protects them. Eventually their teeth are ground down to a chiseled edge due to the constant gnawing on trees. This may make the Beaver seem frightening but the North American Beaver is a herbivore and does not eat meat. These large and very strong teeth make it possible for the North American Beaver to chew through large trees at a relatively fast pace allowing them to construct their homes and lodges within days, and also allows them to get to the under lying parts of the tree that is the main source of the North American Beavers diet. Environmental pressures that would have caused this would not exist. The need to eat and chop down trees as a home and food source would have caused this adaptation. The Beaver needed to build its home, and needed to eat, so they developed large strong teeth so they could chop down trees quick and efficiently.
Physiological
A physiological adaptation that the North American Beaver has is its warm blood. Being warm blooded allows the North American Beaver to stay underwater for long times without getting cold and getting hypothermia. As long as the Beaver keeps its energy levels up its internal systems can keep generating heat so that the Beaver can keep warm under water. This also benefits if the surroundings are warm. The Beaver can cool itself to remain at a comfortable temperature and continue on with building its lodge and keeping its family safe. The environmental pressure that would give the North American Beaver warm blood would come from its ancestor, the Ancient Giant Beaver. This Beaver was tested by nature and put through an ice age, and its warm blood kept it alive. This trait was passed through to the North American Beaver.
Other Information
These days the North American Beaver is a symbol of Canada and renowned to be natures own engineer. Able to survive harsh weather, live comfortably within its own built lodge, and its ability to be a sufficient swimmer and land dweller makes the North American Beaver a very unique creature. The Beaver is recognized in many schools and communities for its skill and unique building. It is said that many engineers and designers use the Beaver as inspiration for structures as it is such a well build lodge built by nothing more than a large rodent.
Sources
BBC - Science & Nature - Wildfacts - North American beaver, Canadian beaver. (n.d.). BBC - Homepage. Retrieved July 21, 2010, from http://www.bbc.co.uk/nature/wildfacts/factfiles/615.shtml
Beaver - Castor canadensis - NatureWorks. (n.d.). New Hampshire Public Television - Engage. Connect. Celebrate.. Retrieved July 21, 2010, from http://www.nhptv.org/natureworks/beaver.htm
Beavers Natural Engineers. (n.d.). hsus. Retrieved July 21, 2010, from www.hsus.org/wildlife/a_closer_look_at_wildlife/beavers_natures_engineers.html
North American Beaver - Wikipedia, the free encyclopedia. (n.d.).Wikipedia, the free encyclopedia. Retrieved July 21, 2010, from http://en.wikipedia.org/wiki/North_American_Beaver
Silverman, J. (n.d.). HowStuffWorks "Why do beavers build dams? ".Howstuffworks "Animals". Retrieved July 21, 2010, from http://animals.howstuffworks.com/mammals/beaver-dam.htm
Images courtesy of: north american beaver - Flickr: Search. (n.d.). Welcome to Flickr - Photo Sharing. Retrieved July 21, 2010, from http://www.flickr.com/search/?q=north+american+beaver&z=e
The Beaver. (n.d.). Straight talk about issues affecting America today: America's Christian Heritage, Separation of Church and State, Abortion, Evolution. Retrieved July 28, 2010, from http://www.straight-talk.net/evolution/beaver.htm